1. Technical Field
The present invention relates to a printing apparatus including a suction groove and a suction hole adsorbing and supporting a printing medium in a printing medium support unit supporting the printing medium supplied to a print execution area.
2. Related Art
An ink jet printer which is an example of a printing apparatus will be described below. Among ink jet printers, there is an ink jet printer including a suction groove and a suction hole adsorbing and supporting a printing medium (hereinafter, also referred to as a “sheet”) in a printing medium support unit (hereinafter, also referred to as a “sheet support unit”) supporting the sheet supplied to a print execution area in order to stabilize the position of the sheet during printing, as disclosed in JP-A-2007-98936 and JP-A-2008-254218.
The suction groove may have various forms, as disclosed in JP-A-2007-98936 and JP-A-2008-254218, but the configuration and function of the suction groove are not considerably different between apparatuses. The sheet is adsorbed and supported by the suction force from the suction hole formed in the bottom of the suction groove in a fixed state and a negative pressure generated by blocking the upper surface of the suction groove by the sheet supplied onto the suction groove.
In the configurations of known suction groove and suction hole, however, it is difficult to adsorb and support the sheet relative to the support surface of the sheet support unit, since curling of a roll sheet is large and a distance between the sheet support unit and the sheet is large.
Even in a single sheet cut at a predetermined size, it is also difficult to adsorb and support the sheet relative to the support surface of the sheet support unit, when the end edge or the corners of the sheet may be curved and thus may be curled up.
When the sheet is not reliably adsorbed and supported relative to the support surface of the sheet support unit, a desired print quality may not be ensured. Moreover, transport trouble of the sheet may arise in that a print head may touch the print surface of the sheet or sheet may be jammed.